12
14.2 Liquid line pressure charging and refrigerant
adjustment in cooling (above 55°F outdoor temp.)
Sealed-System Repairs — Calculating total system charge.
1. Total Line Length (ft)
2. Standard Line set (ft)
3. (a) minus (b)
4. Refrigerant Multiplier
5. Refrigerant Adder (c*d)
6. Factory Charge (nameplate)
7. Total System Charge (e+f)
*If line set is less than 15 feet, (e) = 0
The only mode approved for validating system charge is while in
Cooling Mode. Outdoor Temperature must be between 55°F and
115°F with Indoor Temperature kept between 70°F and 80°F.
Check the outdoor ambient temperatures.
Liquid line pressure (in cooling mode) is the only recommended
method of charging above 55ºF outdoor ambient temperatures.
For outdoor ambient temperatures below 55ºF , use weigh-in charge
method.
Note
:It is important to return in the spring or summer to accurately
charge the system in the cooling mode when outdoor ambient
temperature is above 55ºF.
For best results the indoor temperature should be kept between 70ºF
to 80ºF.
Ensure Sections 7, 8, 9, 10,11,12 and 13 have been completed.
1.
Stabilize the system by operating for a minimum of 20 minutes.
3.
2.
Calculate liquid line pressure (According to Refrigerant Charging
Chart)
4.
55ºF
Outdoor Temp.1
115ºF
Outdoor
Temperature
Above 55ºF
55ºF
Outdoor Temp. 2
Outdoor
Temperature
Below 55ºF
Figure 36
80ºF
70ºF
Indoor Temp.
Figure 37
At startup, or whenever charge is removed or added, the system
must be operated for a minimum of 20 minutes to stabilize before
accurate measurements can be made.
20 MIN
.
Figure 38
Figure 39
Measured Suction Line Pressure = ________PSIG
Outdoor Ambient Temperature = _______ ºF
Calculate Liquid Line Pressure = ________PSIG
= (a)
= 15
(b)
= (c)
=
(d)
= (e*)
= (f)
= _
